CA1264468A - Peroxide compositions and process for producing same - Google Patents
Peroxide compositions and process for producing sameInfo
- Publication number
- CA1264468A CA1264468A CA000471285A CA471285A CA1264468A CA 1264468 A CA1264468 A CA 1264468A CA 000471285 A CA000471285 A CA 000471285A CA 471285 A CA471285 A CA 471285A CA 1264468 A CA1264468 A CA 1264468A
- Authority
- CA
- Canada
- Prior art keywords
- dispersion
- peroxide
- organic peroxide
- water
- particles
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
- C08F2/40—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation using retarding agents
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F4/00—Polymerisation catalysts
- C08F4/28—Oxygen or compounds releasing free oxygen
- C08F4/32—Organic compounds
Abstract
ABSTRACT OF THE DISCLOSURE
Organic peroxide compositions that are available as sprayable dispersions, pourable dispersions, thick pastes and free flowing powder form, all of which may be characterized as slow burning and nonexplosive. Benzoyl peroxide compositions are preferred and may contain up to about 70 weight percent peroxide while viscosity of dispersions of same may be as low as about 100 centipoises when measured with a Brookfield RVT
viscometer using a number 3 spindle at 50 rpm.
Dispersions are produced in low shear, impact-attrition type dispersion mills, exemplified by a Kady Mill.
Organic peroxide compositions that are available as sprayable dispersions, pourable dispersions, thick pastes and free flowing powder form, all of which may be characterized as slow burning and nonexplosive. Benzoyl peroxide compositions are preferred and may contain up to about 70 weight percent peroxide while viscosity of dispersions of same may be as low as about 100 centipoises when measured with a Brookfield RVT
viscometer using a number 3 spindle at 50 rpm.
Dispersions are produced in low shear, impact-attrition type dispersion mills, exemplified by a Kady Mill.
Description
~Z64~6~3 I MPROVED PERQXI DE CC)MPOSI TI ONS AND PROCESS
FOR PRODUCI NG SAME
BACKGXOUND OF THE I NVENTI ON
This invention relates to improved peroxide compositions which, depending upon the constituents of ~:~ same may be pourable or sprayable dispersions, powders or the like, and to a process for producing same.
Organic peroxides, primarily banzoyl peroxide, have ~- been employed as catalysts for unsaturated polyester resin syrups, in spray up techniques, molding, mine bolt applioations, and the like; in pharmaceu~ical ~; compositions; and in general paste applications where the ~; peroxide i3 also a catalyst, as exemplified by use in : reconstruction of automobile bodies. In particular, benzoyl peroxide has been widely utilized, in conjunction with organic plaæticizers such as butyl benzyl phthalate :~ or~dibutyl phthalate, as catalysts in a "split batch~
: æpray up application~of polyester resin syrups. In the ; split batch process, a firæ~t resin syrup includes a ~ catalyst promoter:diæsolved therein while a second, ~ saparate re~sin syrup~has the benzoyl peroxide catalyst -~ di:ssolved therein. The two resin syrups are independently pumped to the head of a spray gun where : they are mixed and sprayed onto the receiving surface, ~5 per se, or in conjunction with a reinforcing:medium such ~: as chopped g]ass fibers. More recently methyl ethyl~
~ketone peroxias h~s been utilized as a low viscosity, sprayable liquid which obviated the split batch method ; ~and replaced same with a single resin syrup pump plus a pre~surized catalyst pot. A small catalyst line delivers ~:~ the methyl ethyl Xetone peroxide to the spray head,~and represents a much simpli~ied spray up system, though:the ;:
: methyl ethyl ketone peroxide has a bad odour, is toxic, ~ .
:~; ,Y i ~. ... . , . . ~ .':
" ~ .
: , ' ;;' , ':
and i 6 flammable.
It i8 likewise known in the art that the polyester producks may be produced as low density foams or high density ~olid produat~ by the presence or absence of blowing agents in the polymer mix. U.S. Patent 3,224,983 to D'Alello fox example, describes the use of organic carbonates which, when heated, liberate aarbon dioxiae as a blowing agent for varlous thermoplastic re~ins along with a disclosure of lowering of the temperatuxe at which lQ carbon dioxide is liberated by an activator which may be an inorgania acid, base or salt exemplified by sodium carbonate and sodium bicarbonate. In like fashion, U.S.
;; Patent 3,470,114 to Siegel et al, discloses the preparation of foamed unsaturated polyesters wherein carbon dioxiae is generated from an aromatic `~ polycarbonate. Foamed unsaturated polyester products are also disclosed in U.S. Patents 3,884,844; 3,920,589;
4,028,289; 4,016,112; 9,028,289; and 4,119,583.
The prior patented art further discloses stable peroxide dispers~ons including dispersions of benzoyl . peroxide which contain activated gels, including finely divided silicas, exemplified by Cab-o-sil , a silica product manu~actured by Cabot Corporation, soston~
Massachusetts that are activated in the process.
In addition to the above dlsclosures of the patented prior art, Witco Chemiaal, U.S. Peroxygen ~ivision, 850 Morton Avenue, Richmond, California 94804 and Noury Chemical Corporation, Burt, New York 14028 manufacture and market commercial ~uspensions or dispersions of ~; 30 benzoyl peroxide. The particular commercially available suspensions or dispersions of benzoyl peroxide, while analogous to the products of the present invention, are guite distinct from same as will become evident hereinafter. Notably, the Witco and Noury products Trademark ., ' .
. ::
. .
,: ' ' ' ~, , . ~:
:~ ' ' . :
.: :, ' -12~
possess viscosity limitations not present with the products of the present invention and thus limit the applicability of same. Specifically, viscosity of the presently commercially available products fall in a range of about 2,000 centipoises up, while those of the present invention as will be specifically described hereinafter, are available at viscosity levels in a range of from about 100 centipoises up. Furthermore, whereas the pxesently commercially available products are primarily classified by the Department of ~ransportation as hazardous due to the flammable and explosive nature of ~ame, produats according to the present invention are not so clas6ified, and, in fact, in certain forms are not explosive and burn only very slowly. Still further, due to the viscosity limltations of the prior art products, the amount of ben~oyl peroxide present in the dispersions has likewise been limited at an upper level somewhere in the neighborhood of 50 to 55 percent by weight, whereas with present products the concentration of peroxide may be up to about 70 weight percent.
It will thus be readily ascertainable from the following description that products according to the present invention as well as the process for producing ~` same will greatly modify utilization or organic peroxide pro~ucts. Since the products are not classified as ~j hazardous materials, restrictions will not exist as to the quantity in a single package; the transportation requirements for same; the handling of same in the plant;
and the like. Moreover, utilizatlon of products according to the present invention will primarily replace methyl ethyl ketone peroxide catalysts, which are highly toxic, flammable, etc. as catalysts for unsaturated polyester resin syrups, though the prior art is repleat with disclosures of uses to which the present compositions may be emplo~ed as well as to the individual .:
~3 ,~
. ~, . ~, ... ... .. .
..` , ~ .
~l2~ L6~3 disclosed constituents of the compositions, there is no teaching or suggestion in any known prior art as to the present process for production of peroxide dispersions nor to the particular improvea products produced thereby.
: S SI~M~Y OF THE I NVEMTI ON
It is an object of the present invention to provide an improved dispersion of an organic peroxide in water.
Anothe.r object o the present invention is to provide;a low viscosity~ sprayable bënzoyl peroxide dispersion in water.
Yet another ob~ect of the present invention is to provids an improved benzoyl peroxide dispersion, the viscosity of which may vary to permit the dispersion to be sprayed or utilized as a thickened paste depending upon a particular end use, and without explosive hazard.
Still further another object of the present invention is to provide an improved organic peroxide dispersion in water that will not explode, burn or pollute the surroundings.
Yet ànother object of the present invention is to provide an improved aqueous dispersion of benzoyl peroxide which upon drying wiIl not create a fire or explosive hazard.
Still another ob~ect of the pressnt invention is to ~`; 25 provide an improved process for the production of aqueous dispersions of organic peroxides.
Still a further object of the present invention is to provide a proce~s for the production of very fine particle size benzoyl peroxide powder.
Generally 3peaking organic peroxide dispersions according to teachings of the present invention oomprise an organic peroxide in particulate form in a range o~
from about 35 to 70 peroent by weight of the dispersion;
water; and a compound whioh when disper~ed in conjunation with the peroxide and water will create an ionio region '' ~ `, ~' ' . .,. ~ ~
. `, . ..
46~3 around the peroxide particles, is inert to the peroxide, and is at least water dispersible and which will permit the attainment of the dispersion viscosity as low as about 100 centipoise~ as determined by a Brookfield RV~
viscometer at 25 degrees centigrade using a number 3 spindle at 50 revolutions per minute.
More specifically, the basic peroxide dispersion as ~` set forth above may likewise include a number of furtheringredients to permit the dispersion to be utilized for particular end uses and to impart certain desirable ~ oharacteristics thereto. sy way of exampls, a defoamer - is normally included to reduce the incidence of oamingof the dispersion and is preferably present for most end uses. Further, the inclusion of a water soluble inorganic salt in the dispersion renders the suspension or dispersion stable, and retains the peroxide in suspen6ion. Such salts which must be stable as to the peroxide may include sodium chloride, potassium chloride, ; calcium chloride ana most other ahloride salts except those of the transition metals which will cause the peroxide to decompose. Also, the soluble phosphate and sulfate salts of the group I and II metals are also generally acceptable.
Dispersions of organic peroxides according to the present invention when utilized as catalyst for unsaturated polyester resins or monomers may also include : carbonate or bicarbonate salts of the group I or II
metals whereby a variance of the amount of catalyst employed will produce a low density, foamæd or a high density polymer product. The carbonate or bicarbonate saIts liberate carbon dioxide which serves as a blowing ; agent for the polyester or the like to foam same when ~; present in adequate quantity.
Acidia inorganla salts may also be included in the ~; 35 disper~ion, attributing a number of beneficial aspects ~,~
' :`~ '` ' -:
, ~:. `',. :
gL2~
thereto. Specifically, such salts, exemplified by NaH2P0, Na2HP04, NaHS04 and AlCl3 increase specific gravity of the water phase and thereby decrease settling propensity of the peroxide; act as a fire retardant for the peroxide in suspension; serve as a humectant whereby the rate of water evaporation from the dispersion is reduced; and retain the water of hydration after drying of the dispersion to negate any fire hazard that is normally experienced with the dry peroxides. As to the particular inorganic salts, sodium dihydrogen phosphate and sodium hydrogen phosphate are paxticularly beneficial for, in addition to the above attributes, these particular phosphates serve as natural buffer~ for the system and maintain pH in a range of about 3 to about 8, and act as sequestrants, thereby reducing the likelihood ~ decomposition of the peroxlde due to transition metal ; ions. Products according to the pre~ent invention may be employed, without danger of fire or explosive hazard in spray up systems as catalysts for resin syrups; as thickened pastes in curing of resin syrups or pastes in mine bolt-applications, in repair of structured elements or the liXe; as active ingredients in dermicidal and other pharmacsutical compositions, and the like.
The process of producing dispersions according to the present invention generally comprises the steps of providing a mixture of the constituents for the dispersion, subjecting the mixture to a low shear, attrition type dispersion mill for a predetermined period of time, removing the resulting dispersion and degassing same.
More specifically, the predetermined constituents of ~ the dispersion with the exceptions of the peroxide are - preferably first blended in a low shear mixer after which the blend i8 added to a low shear attrition type ; ~
dispersion mill. '~he particulate peroxide is then added . .
.
.
~L26~468 to the blend in the dispersion mill and the mill is operated for a predetermined time to produce the desired dispersion. Viscosity of the dispersion is determined by the constituents and the time of operation of the dispersion mill. Thereafter, the disp~rsion is removed from the dispersion mill and is preferably degassed and iltered.
By utilization of ~he lower shear, attrition type dispersion mill, preferably a Kady Mill, as described hereinafter, and a compound that produces an ionic region about the peroxide particles, viscosity can be controlled from a very low viscosity eg. about 100 centipoises to a very high viscosity eg. 15,000 centipoises or greater.
At the low viscosities, the dispersion is sprayable in conventional spray e~uipment without damage or fouling while at the higher viscosities a thick paste results.
For both type applications, as well as others in medium viscosity ranges, additional constituents may be added to th~ dispersion to stabilize the dispersion, reduce the flammable and explosive nature of the peroxide even after drying of the dispersion, for ~oaming a polymer and the like.
BRIE~ DESCRIPTION OE THE FIGURE
~, :
Figure 1 is ~ sohematic top plan view of a portion ~of the operation elements of a Kady Mill type dispersion unit.
- ~igure 2 is an enlarged Yiew of a portion of Figure '~"~ 1.
ESCRIPTION OF THE_PREFERREp EMBODIMEN~S
Peroxide compositions according to the present invention may be employed in a number of different environs, realizing improvement in each due to the nature and characteristics of the compositions. By way of ~; example, the peroxides are well known as catalysts for polymerization of unsaturated polyester resins.
, -.,., ;
.
.. ..
'' ' ' ' ;, '-.; . ':
~:6~468 g Historically, the peroxide composi tions of the prior arthave been limited by their nat:ure to particular techniques. Specifically as to benzoyl peroxide which i5 a preferred peroxide according to the present teachings the dispersions, suspensions, pastes or the like of the prior art have been very viscous. Employment of prior compositions in spray up techniques, for example, as mentioned hereinbefore, has required dual pumpi ng ~ystems, the result of which has led to the demise of the use of the benzoyl peroxide as a catalyst in spray up operations in favour of the liquid methyl ethyl ketone peroxides. While the methyl ethyl ketone peroxides are sprayable, the products are also very volatile, very toxic, very odoriferous and require solvent cleanup operations. Particularly the flammability and toxicity of the methyl ethyl ketone peroxides dictates stringent handling requirements for safe use. Similarly as to the peroxide aompositions, the normal explosive nature of the same has previously required severe restrictions on transport of product, on the storage of product at the point use, and on the actual use of product in industrial operations. Not only do the flammability and explosive problems of the peroxides present real safety hazards, ~- the restrictions on transport and storage also add severely to the economics of using same in any operation.
The peroxide products according to the present ~; invention, are not classified as hazardous chemicals due to the fact that they may be produced in a virtually nonflammable, nonexplosive form, even in a dry state.
Declas ification o the present peroxide compositions ~ enables the compositions to be transported, stored and - used without the restrictio~s placed on the prior art compositions, all leading to i.mproved efficiency and use wlth attendant less expense. Not only, however, do compositions according to the present invention enjoy the : ~
, ~
. .
.
:':
. .
.
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~64'~613 aforementioned benefits, likewise the particular compositions may be manufactured ln wide viscosity ranges to a point where they are now quite suitable for use in processes that were heretofore unavailable for peroxide dispersions.
Organic peroxides that may be suita~ly employed according to teachings of the present invention include solid peroxides that are dispersible in an aqueous medium as exemplified by benzoyl peroxide, lauroyl peroxide, di-cumyl peroxide, and di-cetyl peroxydicarbonate. Benzoyl peroxide is the preferred peroxide for use according to the present invention, and will be specifically discussed hereinafter as representative of the genus.
Depending upon the overall composition of the peroxide products according to the present invention, different uses may be made of same. Dispersions or ~; suspensions of the peroxide may range from very low viscosity, sprayable compositions for catalysis of : unsaturated monomers, polyester resin syrups, etc. to very viscous dispersions in virtually paste form which likewise would be sul~able for catalysis, but in molding operatione, mine bolt securement, repair of structured elements in which the materials are poured or spread by hand or the like. Additionally, present compositions may ~ 25 be pxovided in which the peroxide is present in very ;`` finely divided powder form while still characterized as non-hazardous from a standpoint of flammability and/or ::`
explosion.
While the use of organic peroxide compositions are alluded to as catalysts for unsaturated polyester resin syrups, it is likewise known to use peroxides as aatalysts for polymeriæation of other monomers, ~- copolymers, and the like in which ethylenic unsaturation present, e.g. monomeric vinyl, acrylic, ana styrene ;~ 35 resins, polyester resins, and copolymers of same.
,.:
~, :
, . .
~~.
~L26~46~3 Hereinafter, discussion of only the polyester resin syrup compositions are described though it is not intended that the present application be restricted thereto.
Unsaturatea polyester resin syrups which may be S catalyzed by the peroxide compositions of the present invention include unsaturated polyester resins having a copolymerizable monomer which contains a terminal vinyl group. The unsaturated polyester resin may be derived from the polyesterification of a polycarboxylic acid or a polycarboxylic acid anhydride with a polyol according to techni~ues well known to those skilled in the art. Since the polyestsr resin to be produced is unsaturated, the polycarboxylic acid or anhydride, the polyol, or both must contain at least one ethylenically unsaturated bond in the structure. Exemplary of polycarboxylic acids and anhydrides which are suitable for use in production of the unsaturated polyesters include wit~out li~itation, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, succlnic acid, tetrahydrophthalic acid, tetrabromophthalic acid, maleic acid, fumaric acid, the ~i anhydride of any of the aforementioned acids, and combinations thereof. Polyols suitable for use in ~ preparation of the unsaturated polyester resins are -~ exemplified by ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, polyethylene glyaol, polyprop.ylene glycol, trimethylol ethane, trimethylol propane, pentaerythritol, hydroxy-alkyl esters of polycarboxylic aoids and combination6 thereof. As is well known to those skilled in the art, a slight s~oichoimetric excess of polyol is generally employed in preparation of the polyester resin to ~acilitate reaction between the polyoarboxylic acid or anhydride and the poly~l and to reduce the viscosity of the formed polyester resin.
A copolymerizable monomer is combinable with the :
:;;
L~
;
:
4~3 unsaturated polyester resins to yield a liquid resin syrup containing a terminable vinyl group. Such monomers are exemplified by styrene, alpha-methyl styrene, o-chlorostyrene, vinyl toluene, acrylic acid, methacrylic S acid, alkyl acrylates, alkyl methacrylates, di~i nyl benzene, d.iacrylate~, dimethacrylates, triacrylates, trimethacrylates and combinations thereof. In general, the monomer may be provided in an amount which falls in a r~nge of from about 20 to about 40% of the total weight of the resin syrup, and, when reacted with the unsaturated polyester resins, produces a crosslinked polymer structure. Further suitable copolymerizable monomers for the resin syrup include the reaction products of polyzpoxides with acrylic or methacrylic acids; eg. the reaction products o~ a polyol such as
FOR PRODUCI NG SAME
BACKGXOUND OF THE I NVENTI ON
This invention relates to improved peroxide compositions which, depending upon the constituents of ~:~ same may be pourable or sprayable dispersions, powders or the like, and to a process for producing same.
Organic peroxides, primarily banzoyl peroxide, have ~- been employed as catalysts for unsaturated polyester resin syrups, in spray up techniques, molding, mine bolt applioations, and the like; in pharmaceu~ical ~; compositions; and in general paste applications where the ~; peroxide i3 also a catalyst, as exemplified by use in : reconstruction of automobile bodies. In particular, benzoyl peroxide has been widely utilized, in conjunction with organic plaæticizers such as butyl benzyl phthalate :~ or~dibutyl phthalate, as catalysts in a "split batch~
: æpray up application~of polyester resin syrups. In the ; split batch process, a firæ~t resin syrup includes a ~ catalyst promoter:diæsolved therein while a second, ~ saparate re~sin syrup~has the benzoyl peroxide catalyst -~ di:ssolved therein. The two resin syrups are independently pumped to the head of a spray gun where : they are mixed and sprayed onto the receiving surface, ~5 per se, or in conjunction with a reinforcing:medium such ~: as chopped g]ass fibers. More recently methyl ethyl~
~ketone peroxias h~s been utilized as a low viscosity, sprayable liquid which obviated the split batch method ; ~and replaced same with a single resin syrup pump plus a pre~surized catalyst pot. A small catalyst line delivers ~:~ the methyl ethyl Xetone peroxide to the spray head,~and represents a much simpli~ied spray up system, though:the ;:
: methyl ethyl ketone peroxide has a bad odour, is toxic, ~ .
:~; ,Y i ~. ... . , . . ~ .':
" ~ .
: , ' ;;' , ':
and i 6 flammable.
It i8 likewise known in the art that the polyester producks may be produced as low density foams or high density ~olid produat~ by the presence or absence of blowing agents in the polymer mix. U.S. Patent 3,224,983 to D'Alello fox example, describes the use of organic carbonates which, when heated, liberate aarbon dioxiae as a blowing agent for varlous thermoplastic re~ins along with a disclosure of lowering of the temperatuxe at which lQ carbon dioxide is liberated by an activator which may be an inorgania acid, base or salt exemplified by sodium carbonate and sodium bicarbonate. In like fashion, U.S.
;; Patent 3,470,114 to Siegel et al, discloses the preparation of foamed unsaturated polyesters wherein carbon dioxiae is generated from an aromatic `~ polycarbonate. Foamed unsaturated polyester products are also disclosed in U.S. Patents 3,884,844; 3,920,589;
4,028,289; 4,016,112; 9,028,289; and 4,119,583.
The prior patented art further discloses stable peroxide dispers~ons including dispersions of benzoyl . peroxide which contain activated gels, including finely divided silicas, exemplified by Cab-o-sil , a silica product manu~actured by Cabot Corporation, soston~
Massachusetts that are activated in the process.
In addition to the above dlsclosures of the patented prior art, Witco Chemiaal, U.S. Peroxygen ~ivision, 850 Morton Avenue, Richmond, California 94804 and Noury Chemical Corporation, Burt, New York 14028 manufacture and market commercial ~uspensions or dispersions of ~; 30 benzoyl peroxide. The particular commercially available suspensions or dispersions of benzoyl peroxide, while analogous to the products of the present invention, are guite distinct from same as will become evident hereinafter. Notably, the Witco and Noury products Trademark ., ' .
. ::
. .
,: ' ' ' ~, , . ~:
:~ ' ' . :
.: :, ' -12~
possess viscosity limitations not present with the products of the present invention and thus limit the applicability of same. Specifically, viscosity of the presently commercially available products fall in a range of about 2,000 centipoises up, while those of the present invention as will be specifically described hereinafter, are available at viscosity levels in a range of from about 100 centipoises up. Furthermore, whereas the pxesently commercially available products are primarily classified by the Department of ~ransportation as hazardous due to the flammable and explosive nature of ~ame, produats according to the present invention are not so clas6ified, and, in fact, in certain forms are not explosive and burn only very slowly. Still further, due to the viscosity limltations of the prior art products, the amount of ben~oyl peroxide present in the dispersions has likewise been limited at an upper level somewhere in the neighborhood of 50 to 55 percent by weight, whereas with present products the concentration of peroxide may be up to about 70 weight percent.
It will thus be readily ascertainable from the following description that products according to the present invention as well as the process for producing ~` same will greatly modify utilization or organic peroxide pro~ucts. Since the products are not classified as ~j hazardous materials, restrictions will not exist as to the quantity in a single package; the transportation requirements for same; the handling of same in the plant;
and the like. Moreover, utilizatlon of products according to the present invention will primarily replace methyl ethyl ketone peroxide catalysts, which are highly toxic, flammable, etc. as catalysts for unsaturated polyester resin syrups, though the prior art is repleat with disclosures of uses to which the present compositions may be emplo~ed as well as to the individual .:
~3 ,~
. ~, . ~, ... ... .. .
..` , ~ .
~l2~ L6~3 disclosed constituents of the compositions, there is no teaching or suggestion in any known prior art as to the present process for production of peroxide dispersions nor to the particular improvea products produced thereby.
: S SI~M~Y OF THE I NVEMTI ON
It is an object of the present invention to provide an improved dispersion of an organic peroxide in water.
Anothe.r object o the present invention is to provide;a low viscosity~ sprayable bënzoyl peroxide dispersion in water.
Yet another ob~ect of the present invention is to provids an improved benzoyl peroxide dispersion, the viscosity of which may vary to permit the dispersion to be sprayed or utilized as a thickened paste depending upon a particular end use, and without explosive hazard.
Still further another object of the present invention is to provide an improved organic peroxide dispersion in water that will not explode, burn or pollute the surroundings.
Yet ànother object of the present invention is to provide an improved aqueous dispersion of benzoyl peroxide which upon drying wiIl not create a fire or explosive hazard.
Still another ob~ect of the pressnt invention is to ~`; 25 provide an improved process for the production of aqueous dispersions of organic peroxides.
Still a further object of the present invention is to provide a proce~s for the production of very fine particle size benzoyl peroxide powder.
Generally 3peaking organic peroxide dispersions according to teachings of the present invention oomprise an organic peroxide in particulate form in a range o~
from about 35 to 70 peroent by weight of the dispersion;
water; and a compound whioh when disper~ed in conjunation with the peroxide and water will create an ionio region '' ~ `, ~' ' . .,. ~ ~
. `, . ..
46~3 around the peroxide particles, is inert to the peroxide, and is at least water dispersible and which will permit the attainment of the dispersion viscosity as low as about 100 centipoise~ as determined by a Brookfield RV~
viscometer at 25 degrees centigrade using a number 3 spindle at 50 revolutions per minute.
More specifically, the basic peroxide dispersion as ~` set forth above may likewise include a number of furtheringredients to permit the dispersion to be utilized for particular end uses and to impart certain desirable ~ oharacteristics thereto. sy way of exampls, a defoamer - is normally included to reduce the incidence of oamingof the dispersion and is preferably present for most end uses. Further, the inclusion of a water soluble inorganic salt in the dispersion renders the suspension or dispersion stable, and retains the peroxide in suspen6ion. Such salts which must be stable as to the peroxide may include sodium chloride, potassium chloride, ; calcium chloride ana most other ahloride salts except those of the transition metals which will cause the peroxide to decompose. Also, the soluble phosphate and sulfate salts of the group I and II metals are also generally acceptable.
Dispersions of organic peroxides according to the present invention when utilized as catalyst for unsaturated polyester resins or monomers may also include : carbonate or bicarbonate salts of the group I or II
metals whereby a variance of the amount of catalyst employed will produce a low density, foamæd or a high density polymer product. The carbonate or bicarbonate saIts liberate carbon dioxide which serves as a blowing ; agent for the polyester or the like to foam same when ~; present in adequate quantity.
Acidia inorganla salts may also be included in the ~; 35 disper~ion, attributing a number of beneficial aspects ~,~
' :`~ '` ' -:
, ~:. `',. :
gL2~
thereto. Specifically, such salts, exemplified by NaH2P0, Na2HP04, NaHS04 and AlCl3 increase specific gravity of the water phase and thereby decrease settling propensity of the peroxide; act as a fire retardant for the peroxide in suspension; serve as a humectant whereby the rate of water evaporation from the dispersion is reduced; and retain the water of hydration after drying of the dispersion to negate any fire hazard that is normally experienced with the dry peroxides. As to the particular inorganic salts, sodium dihydrogen phosphate and sodium hydrogen phosphate are paxticularly beneficial for, in addition to the above attributes, these particular phosphates serve as natural buffer~ for the system and maintain pH in a range of about 3 to about 8, and act as sequestrants, thereby reducing the likelihood ~ decomposition of the peroxlde due to transition metal ; ions. Products according to the pre~ent invention may be employed, without danger of fire or explosive hazard in spray up systems as catalysts for resin syrups; as thickened pastes in curing of resin syrups or pastes in mine bolt-applications, in repair of structured elements or the liXe; as active ingredients in dermicidal and other pharmacsutical compositions, and the like.
The process of producing dispersions according to the present invention generally comprises the steps of providing a mixture of the constituents for the dispersion, subjecting the mixture to a low shear, attrition type dispersion mill for a predetermined period of time, removing the resulting dispersion and degassing same.
More specifically, the predetermined constituents of ~ the dispersion with the exceptions of the peroxide are - preferably first blended in a low shear mixer after which the blend i8 added to a low shear attrition type ; ~
dispersion mill. '~he particulate peroxide is then added . .
.
.
~L26~468 to the blend in the dispersion mill and the mill is operated for a predetermined time to produce the desired dispersion. Viscosity of the dispersion is determined by the constituents and the time of operation of the dispersion mill. Thereafter, the disp~rsion is removed from the dispersion mill and is preferably degassed and iltered.
By utilization of ~he lower shear, attrition type dispersion mill, preferably a Kady Mill, as described hereinafter, and a compound that produces an ionic region about the peroxide particles, viscosity can be controlled from a very low viscosity eg. about 100 centipoises to a very high viscosity eg. 15,000 centipoises or greater.
At the low viscosities, the dispersion is sprayable in conventional spray e~uipment without damage or fouling while at the higher viscosities a thick paste results.
For both type applications, as well as others in medium viscosity ranges, additional constituents may be added to th~ dispersion to stabilize the dispersion, reduce the flammable and explosive nature of the peroxide even after drying of the dispersion, for ~oaming a polymer and the like.
BRIE~ DESCRIPTION OE THE FIGURE
~, :
Figure 1 is ~ sohematic top plan view of a portion ~of the operation elements of a Kady Mill type dispersion unit.
- ~igure 2 is an enlarged Yiew of a portion of Figure '~"~ 1.
ESCRIPTION OF THE_PREFERREp EMBODIMEN~S
Peroxide compositions according to the present invention may be employed in a number of different environs, realizing improvement in each due to the nature and characteristics of the compositions. By way of ~; example, the peroxides are well known as catalysts for polymerization of unsaturated polyester resins.
, -.,., ;
.
.. ..
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~:6~468 g Historically, the peroxide composi tions of the prior arthave been limited by their nat:ure to particular techniques. Specifically as to benzoyl peroxide which i5 a preferred peroxide according to the present teachings the dispersions, suspensions, pastes or the like of the prior art have been very viscous. Employment of prior compositions in spray up techniques, for example, as mentioned hereinbefore, has required dual pumpi ng ~ystems, the result of which has led to the demise of the use of the benzoyl peroxide as a catalyst in spray up operations in favour of the liquid methyl ethyl ketone peroxides. While the methyl ethyl ketone peroxides are sprayable, the products are also very volatile, very toxic, very odoriferous and require solvent cleanup operations. Particularly the flammability and toxicity of the methyl ethyl ketone peroxides dictates stringent handling requirements for safe use. Similarly as to the peroxide aompositions, the normal explosive nature of the same has previously required severe restrictions on transport of product, on the storage of product at the point use, and on the actual use of product in industrial operations. Not only do the flammability and explosive problems of the peroxides present real safety hazards, ~- the restrictions on transport and storage also add severely to the economics of using same in any operation.
The peroxide products according to the present ~; invention, are not classified as hazardous chemicals due to the fact that they may be produced in a virtually nonflammable, nonexplosive form, even in a dry state.
Declas ification o the present peroxide compositions ~ enables the compositions to be transported, stored and - used without the restrictio~s placed on the prior art compositions, all leading to i.mproved efficiency and use wlth attendant less expense. Not only, however, do compositions according to the present invention enjoy the : ~
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~64'~613 aforementioned benefits, likewise the particular compositions may be manufactured ln wide viscosity ranges to a point where they are now quite suitable for use in processes that were heretofore unavailable for peroxide dispersions.
Organic peroxides that may be suita~ly employed according to teachings of the present invention include solid peroxides that are dispersible in an aqueous medium as exemplified by benzoyl peroxide, lauroyl peroxide, di-cumyl peroxide, and di-cetyl peroxydicarbonate. Benzoyl peroxide is the preferred peroxide for use according to the present invention, and will be specifically discussed hereinafter as representative of the genus.
Depending upon the overall composition of the peroxide products according to the present invention, different uses may be made of same. Dispersions or ~; suspensions of the peroxide may range from very low viscosity, sprayable compositions for catalysis of : unsaturated monomers, polyester resin syrups, etc. to very viscous dispersions in virtually paste form which likewise would be sul~able for catalysis, but in molding operatione, mine bolt securement, repair of structured elements in which the materials are poured or spread by hand or the like. Additionally, present compositions may ~ 25 be pxovided in which the peroxide is present in very ;`` finely divided powder form while still characterized as non-hazardous from a standpoint of flammability and/or ::`
explosion.
While the use of organic peroxide compositions are alluded to as catalysts for unsaturated polyester resin syrups, it is likewise known to use peroxides as aatalysts for polymeriæation of other monomers, ~- copolymers, and the like in which ethylenic unsaturation present, e.g. monomeric vinyl, acrylic, ana styrene ;~ 35 resins, polyester resins, and copolymers of same.
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~L26~46~3 Hereinafter, discussion of only the polyester resin syrup compositions are described though it is not intended that the present application be restricted thereto.
Unsaturatea polyester resin syrups which may be S catalyzed by the peroxide compositions of the present invention include unsaturated polyester resins having a copolymerizable monomer which contains a terminal vinyl group. The unsaturated polyester resin may be derived from the polyesterification of a polycarboxylic acid or a polycarboxylic acid anhydride with a polyol according to techni~ues well known to those skilled in the art. Since the polyestsr resin to be produced is unsaturated, the polycarboxylic acid or anhydride, the polyol, or both must contain at least one ethylenically unsaturated bond in the structure. Exemplary of polycarboxylic acids and anhydrides which are suitable for use in production of the unsaturated polyesters include wit~out li~itation, phthalic acid, isophthalic acid, terephthalic acid, adipic acid, succlnic acid, tetrahydrophthalic acid, tetrabromophthalic acid, maleic acid, fumaric acid, the ~i anhydride of any of the aforementioned acids, and combinations thereof. Polyols suitable for use in ~ preparation of the unsaturated polyester resins are -~ exemplified by ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, polyethylene glyaol, polyprop.ylene glycol, trimethylol ethane, trimethylol propane, pentaerythritol, hydroxy-alkyl esters of polycarboxylic aoids and combination6 thereof. As is well known to those skilled in the art, a slight s~oichoimetric excess of polyol is generally employed in preparation of the polyester resin to ~acilitate reaction between the polyoarboxylic acid or anhydride and the poly~l and to reduce the viscosity of the formed polyester resin.
A copolymerizable monomer is combinable with the :
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4~3 unsaturated polyester resins to yield a liquid resin syrup containing a terminable vinyl group. Such monomers are exemplified by styrene, alpha-methyl styrene, o-chlorostyrene, vinyl toluene, acrylic acid, methacrylic S acid, alkyl acrylates, alkyl methacrylates, di~i nyl benzene, d.iacrylate~, dimethacrylates, triacrylates, trimethacrylates and combinations thereof. In general, the monomer may be provided in an amount which falls in a r~nge of from about 20 to about 40% of the total weight of the resin syrup, and, when reacted with the unsaturated polyester resins, produces a crosslinked polymer structure. Further suitable copolymerizable monomers for the resin syrup include the reaction products of polyzpoxides with acrylic or methacrylic acids; eg. the reaction products o~ a polyol such as
2,2,bis-(4 hydroxyphenyl~ propane with a glycidyl acrylate or methacrylate. Generally if employed, this partlcular type of copolymerizable monomer which is in ~, effect a reaction product is employed in lieu of a portion of the unsaturated polyester resin.
In producing the peroxide containing compositions according to the present invention, certain of the procedures to which the constituents are subjected are quits important. Most importantly perhaps is subjecting the constituent to low shear action in process equipment which through impact and/or attrition forces produces an : aqueous dispersion of the peroxide. A Kady Mill manufactured by the Kinetic Dispersion Corporation is an example of such equipment. Generally speaking, and :, referring to Figures 1, and 2 in a Kady Mill d~spersion ~`~ unit, a rotor 20 having tangential slot like structures `~ 22 defined by the rotor blades 23 is rotatably located within a stationary annular stator 3G in which radial slots 32 are provided that have a small cross section relative to their length. ~he constituents are added to ~`
'~-.,;" j ,~
, . ~' ;~ .
~L2644~8 the mill, enter the rotor which rotates at high speeds, eg. 7500 to 15000 revolutions per minute, and material to be dispersed passes through the tangential rotor slots at high speed where they are abruptly stopped by the stationary side walls of the vertical stator slots and their direction is changed. Material enters the rotor-stator mechanism from top and bottom as shown in Figure 1, generally being aided by low agitation propellers.
After recirculating through the rotor-stator mechanism several times, the peroxide is attrited into very small particles and a proper dispersion is formed. The Kady Mill type dispersion avoids shear as much as possible and, in fact, does not rely upon close tolerance between milling surfaces such as colloid mills, ball and pebble mills, rolling mills and the like. ~ime of operation of the Kady Mill is the controlling actor since fixed clearances are built into the mill. Such type of apparatus is described in Vnited States Patent 2,706,621 to Laird. The Kady Mill i6 furthsr specifically described in Cost Enqineexinq, January 1967, pages 2 through 6.
The g~neral process for producing peroxide dispersions according o the present lnvention includes the steps of adding the partiaular constituents to be dispersed to a low shear impact dispersion unit such as the Kady ~ill in which the dispersion is ~uickly achieved, eg. generally in about three to about seven minutes. The dispersion is then removed from the Kady Mill, vacuum degassed and strained. Preferably, prior ~ 30 to introduction of the mixture to the dispersion mill, at ;~ leaBt a portion of same i~ blended with a low shear mixer as exemp].ified by a jiffy mixer. Utilizing the low ~; shear, impact dispersion mill, it was found that a mixture containing water, peroxide in powder or ; 35 particulate form, and a defoamer became very viscous ,' .' ' `
'. ~
:.
-: : .. :
' ~L2~
- ~4 -virtually as soon as the mill was started. When, however, a compound is added that produces an ionic atmosphere about the peroxide particles, is inert as to the peroxide, and is at least water dispersible, viscosities may be achieved as low as about 100 centipoises, msasured with a Brookfield RVT viscometer, numbex 3 spindle at 50 revolutions per minute. Also, inspection with a microscope at 1,000 magnification indicated that all of the peroxide particles were less than 10 microns in size and that a vast majority of same were from about 2 to about 5 microns in size.
Illustrative of the compounds which produce an ionic region about the particles and permit the viscosity ~` control of the peroxide dispersions in the low shear impact dispersion mill are pyrogenic or fumed silicas (Cab-o-sil silicas manufactured by Cabot Corporation), sodlum salts of condensed naphthalene sulfonic acids (Tamol SN, manufactured by Rohm and Haas Company, Philadelphia, Pennsylvania) and sodium salts of polymerized carboxylic acids (~amol 731, manufactured by Rohm and Haas Company). In selecting a particular dispersant for use in controlling viscosity of the dispersion, as mentioned above same must be inert as to the peroxide. In this regard, any compound should be avoided that will, for example, cause the peroxide to decompose, as well as any dispersant in which the peroxide dissolves ~nd promotes the formation of crystalllne peroxide which is shock sensitive and explosive. ~he ionic region ~3enerating compounds may be present in the dispersions in a range of fro~ about 1 to about 7 weight percent, preferably from about 3 to about 6.
In generating the ionic atmosphere about the peroxide particles, particular dispersants, exemplified 3S Trademark . . .
, . : `
; . ~, . ~
, ~6~146~3 by those set forth above, are employed which supply ions to the area surrounding the peroxide particles. Ions, of course, are charged particles which, depending upon charge on ad;acent particles, will create, attract or repulsive forces with respect thereto. The Tamol dispersants noted above are reported in the literature as surrounding particles with a strong anionically charged electrical layer. It is believed that such charged electrical layer overcomes the attractive forces normally existing between the peroxide particles and keeps the particles`separated.
Since benzoyl peroxide is the preferred peroxide for use according to the present invention, discussion ; hereinafter will be made with respect only to benzoyl peroxide with the understanding that other peroxides within the genu~, would likewise be appropriate.
A dlspersion of benzoyl peroxide, water, Cab-o-sil, and a defoamer will, in a short period of time eg.
~everal days, not remain in the dispersed condition. The .
benzoyl peroxide particles will settIe out, but when subjected to low shear agitation, will go back into suspension. In situations where resuspending of the particles will accomplish the intended result, the above dispersion may suffice, shouid, however, it be desirable to produce a permanent dispersion or suspension, a soluble inorganic salt that is stable to the benzoyl : peroxide may be added. Exemplary of such salts are :~ sodium chloride, potassium chloride, and calcium chloride, as well a6 other chloride salts except those of the transition metals which would cause the benzoyl .
.~ peroxide to decompose. Further exemplary of suitable ~` salts are the soluble phosphate and sulfate salts of the group I and II metals. Bromide and iodide salts should, however, be avoided.
~; 35 Inclusion of further particular ingredients in the .
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peroxide compositions when utilizing same to catalyze unsaturated polyester resin E yrups, permit the attainment of a high or a low density polymer product, depending upon the amount of the peroxids composition utilized. A
blowing agent is included which liberatss car~on dioxide, exemplified by carbonates and bicarbonates of groups I or II metals, eg. calcium carbonate or calcium bicarbonate. One sufficient catalyst is included to provide adequate blowing agent for foaming the polymers, foaming wlll occur proportional to the amount present.
A further class of acidic inorganic salts when dissolved in the water phase of the present peroxide compos1tions yields particularly important advantages.
;~ These salts are exemplified by NaH2PO4, Na2HPO4, NaHSO4, or AlCl3, with sodium dihydrogen phosphate and sodium ~: hydrogen phosphate being preferred. The acidic inorganic salt~ (1) increase the specific gravity of the water ~; phase which decreases the propensity of settling of the ~ peroxide; (2) act as a fire retardant for the peroxide in ; 20 suspension; (3) have a humectant effect on the dispersion which reduces the rate of water evaporation therefrom;
and (4) if and when the dispersion dries down or the water is otherwise removed, retain water of hydration which ~ignificantly reduces the flammable and explosive nature of the dry peroxide. In addition, the preferred salts, serve as a buffer to maintain pH of the dispersion in a range of from about 3 to about 8, producs a sequestering effect on the dispersion thu~ reducing decomposition of the peroxide as a result of transition metal ions, and provide a flame retardant effect in both :;` solution and ~olid form. These inorganic salts may be present in the dispersions in a rangs of from about 5 to about 20 weight percent, preferably about 14 to 18 . Additionally othex ingredlents may be added to the dispersions for particular needs so long as no advarse :;-~3 ', .
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effects are produced thereby. For example, a surfactant may be needed for catalysis of certain polyesters, etc.
LiXewise for foamin~, cell stabilizers may be necessary or desirable.
S A better understanding of the present invention will be had by referring to the following examples.
!3~
A mixture of 1500 grams of water, 100 grams of Cab-o-sil , a fumed silica product manufactured by Cabot Corporation and fiO grams of DC-B , a silicone based defoamer manufactured by Dow Corning, Midland, Michigan was added to a low shear mixer and mixed well.
Thereafter, 1906 grams of Lucidol BP0-78 , a particulate ~-~ benzoyl peroxide manufackured by Lucidol Division, ; 15 Pennwalt, Corp., Buffalo, New York, was added to the low shear mixer, mixed in and the mixture was allowed to stand 1 hour. The mixture was then placed in a Kady Mill dispersion unit whi.ch operated for 4.5 minutes, followed by vacuum degassing and straining through an 80 mesh strainer. Visc06ity of the dispersion was measured with a Brookfield RVT viscometer using a number 3 spindle. At 5 rpm a visc06ity reading of 4600 cps. was obtained, while at 50 rpm the visc06ity was 720 cps.
After several days standing undisturbed, the benzoyl peroxide separated from the disper6ion, though thereafter, went back into suspension with low shear agikation. Inspeckion with a microscope at 1000 magnificakion showed all benzoyl peroxide particles to be less than 10 microns, wikh a vask ma~ority of same being a size of from about 2 to about 5 microns. The specific "~ graviky of the dispersion was measured to be 1.158 and ~ peroxide content of 40.9 percenk by weight.
i~ EXAMPLE 2 A mixture of 1200 grams of water, 80 yrams of Cab-o-3S Trademark r ~
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sil and 98 grams of DC-~ defoamer were mixed well in a low shear mixer, after which 2567 grains of Lucidol BP0-78 were added with mixing continuing. ~he overall mixture was then placed in the Kady Mill which operated for three minutes, was removed from the Kady Mill, vacuum degassed and strained through an 80 mesh strainer.
- Viscosity of the dispersion using a number 4 spindle, measured 820 cps. at 100 rpm and 4400 cps. at 10 rpm.
Specific gravity of the dispersion was determined to be 1.150 with 50.2 percent by weight peroxide solids present. The material appeared to be slightly foamed.
ExAMpLE 3 A mixture of 1550 grams water, 60 grams of Cab-o-sil and 80 grams oP DC-120, a silicone based defoamer manufactured by Dow Corning were mixed well in a low shear mixer after which 4022 grams of Luaidol BP0-78 were added and mixed weli. ~his mixture was then placed in the Kady Mill which operated for 7.5 minutes. ~he r~sulting dispersion was removed from the Kady MiIl, vacuum degassed and strained through an 80 mesh strainer.
Viscosity was measured on a Brookfield RVT viscometer with a number 4 spindle to be 1500 cps. at 100 rpm and 6020 at 10 rpm. Speaific gravity of the dispersion was measured at 1.200 with 55.03 percent peroxide solids ;~ 25 present. Examples l through 3 thus indicate preparation ~- of variou~ concentration peroxide dispersions.
Benzoyl peroxide ~BP0) dispersions were produced O.1 the Kady Mill at 35, 40, 45, 50 and 55 weight percent ~ 30 peroxide solids, utilizing proportionate amounts of ;~ water, Cab o~sil and DC-B de~oamer, with the Kady Mill being operated ~or three minutes in each case. Viscosity of each dispersion was measured with a Brookfield viscometer, and results are tabulated in Table 1.
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~ TABLE 1 VISCOSITY OF BPO DISPER~IONS
EXAMPLE NO. 4 S 6 7 8 _ VISCOSITY, CPS. _________ SPEED, RPM
Pounds/Gallon 9.249.35 9.5 9.75 9,g As can be seen from Table I, dispersion viscosities varied from 40 cps. to 8000 cps., depending upon concentration of peroxide solids and the viscosity measurement technique. For a number 3 spindle at 50 rpm, ;~ viscosity ranged from 70 cps. to 620 aps.
EXAMP~ES 9 - 13 A quantity of sodium dihydrogen phosphate was added ~; 20 to each of the dispsrsions of Examples 4 - 8 to produce a 20 weight percent solution of same in the water phase.
Viscosities of the dispersions were then measured.
Results were tabulated in Table II.
TABLE II
VISCOSITY OF BPO-NaH2PO4 DISPERSION
EXAMPLE NO. 9~Q ll 12 13 SPINDLE NO. 23 3 3 4 VIS~O~ITY, CPS.
RVT,RPM 100 60 90 200 810 2500 120250 600 26~0 7000 ~ 10 200 400 1050470Q 1100 ; POUNDS/GA~LON 10.1 10.2 10.3 10.5 10.55 :~ .
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As can be seen from Table II the addition of the sodium dihydrogen phosphate increased viscosities across the board.
.EXAMPLES 14 - 19 A series of BPO dispersions were prepared containing the same percent BP0, DC-B defoamer and water while varylng the level of Cab-o-sil. Each sample was prepared in exactly the same manner. The water, DC-~ defoamer and Cab-o-sil were mixed. The BPO was mixed in slowly in the low shear mixer. The mixtures were subjected to the Kady Mill for an operating time of six minutes. Each sample was then vacuum de~assed and strained. The base constituent mix incluaed 1550 grams of water, 100 grams ;~ of DC-B defoamer, and 3200 grams BPO-78. The Cab-o-sil fumed silica was varied as shown in Table III below with the attendant viscosity measurement for the dispersions~
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As oan he seen ~rom Table III, viscosity followed a U shaped curve. At 0 percent Cab-o-sil, the viscosity was very high, decreasing at 25, 50 and 75 gram levels, then increasing at 100 and 150 gram levels. Such ~as not predicted since Cab-o-sil is marketed as a product to increase viscosity.
EXAMP~ES 19 - 24 Eight hundred grams of each o~ Examples 14 - 19 were mixed well at low shear with 150 grams of sodium dihydrogen phosphate. The sampl~es were left overnight, then vaouum degassed, and visoosity of the dispersion measured. Results are tabulated in Table IV.
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-24- ~ 68 As can be seen from Table IV, the U shaped curve continues to exist, though at a higher plateau.
The samples containing 25, 75 and 100 grams fumed-silica (Examples 15, 17, and 18) were mixed together with low shear for one hour. The Ini x was prepared to be comparable to the original formulation containing 72 grams The viscosity of the resultiny mix was measured with a number 4 spindle and indicated 1250 cps. a~ 100 rpm, 2200 cps. at 50 rpm, 3900 cps. at 20 xpm, 6800 cps.
at 10 rpm and 12350 cps. at 5 rpm. The samples containing 0 and 25 (Examples 14 and 15) grams fumed silica when inspected under the ~icroscope showed the peroxide particles had been broken up and then reaggregated.
A dispersion containing 1550 grams of water, 100 grams of DC -B and 2893 grams of Lucidol BPO-78 was prepared in a low shear mixer as set forth in Example 1.
The mixture was thsn placed in the ~ady Mill for a 1 minute operation. The mixture became so viscous that the mill would not grind. Examination under the microscope indicated reaggregation of the peroxide particles.
Viscosity was tested with a RVT Helipath unit using ` ' 25 Spindle F at 1 rpm and found to be 400 x 106 cps. Sixty grams of Cab o-sil were slowly added to the viscous mix ~ at low shear. Mix viscosity began to drop and the mix ; began to degas. After being mixed well the viscosity of the mix was determined by Brookfield RVT Spindle No. 4 to be 1500 cps. at 100 rpm, 2320 cps. at S0 rpm, 4900 cps.
at 20 rpm and 8000 ~ps. at 10 rpm. The mixture was returned to the Kady Mill for an additional 3 minute operation, removed and degass~d. Viscosity at 50 rpm was 4000 cps. ~hree hundred grams of Tamol SN was slowly ~ mixed in well with low shear. Viscosity dropped to 2500 aps. at 50 rpm. The sample was then vaauum degassed and the visaosity mea~ured using a number 3 spindls.
Visaosity was 7200 cps. at 5 rpm, 4750 aps. at 10 rpm, ~' 1'``' ,~ "'' : ~
~7 ~264L461~
2150 cps. at 20 rpm, 1100 cps. at 50 rpm, and 650 cps. at 100 rpm. Again it is seen that viscosity is in part co~trolled by the fumed silica and a sodium salt of condensed naphthalene sulfuric acid.
A series of dispersions were produced with the constituents as specified in Example 16 with the exception that the level of benzoyl peroxide varied on a weight percent basls as set forth in ~able V below, -~ 10 containing 35, 40, 45, 50, 55, 60 and 65 weight percent benzoyl peroxide. Viscosi~y of the dispersions was measured with a Brookfield viscometer. Results are tabulated in Table V.
TABLE V
VISCOSITY OF BENZOYL PEROXIDE DISPERSIONS
EXAMPLE NO. 27 28 29 BENZOYL PEROXIDE, % 35% 40% 45%
Spindle/rpm- 2/100 = 120 3/100 = 200 3/100 - 350 Vis~.,cps. 2/5~ = 144 3/50 = 280 3/50 = 520 ~` 20 2/20 = 240 3/20 = 175 3/20 = 900 2/10 = 380 3/10 = 750 3/10 = 1500 2/5 = 640 3/5 = 1200 3/5 = 2600 EXAMPhE NO. 30 31 32 ,.i BENZOY~ PEROXIDE, % 50% S5% 60%~Heliapath) .~ . .
Spindle/rpm- 3/100 = 500 5/100 = 1840 D/5 14.8 x 10 Visc.,cps. 3/50= 820 5/50 = 3120 D/25 23.6 x 10
In producing the peroxide containing compositions according to the present invention, certain of the procedures to which the constituents are subjected are quits important. Most importantly perhaps is subjecting the constituent to low shear action in process equipment which through impact and/or attrition forces produces an : aqueous dispersion of the peroxide. A Kady Mill manufactured by the Kinetic Dispersion Corporation is an example of such equipment. Generally speaking, and :, referring to Figures 1, and 2 in a Kady Mill d~spersion ~`~ unit, a rotor 20 having tangential slot like structures `~ 22 defined by the rotor blades 23 is rotatably located within a stationary annular stator 3G in which radial slots 32 are provided that have a small cross section relative to their length. ~he constituents are added to ~`
'~-.,;" j ,~
, . ~' ;~ .
~L2644~8 the mill, enter the rotor which rotates at high speeds, eg. 7500 to 15000 revolutions per minute, and material to be dispersed passes through the tangential rotor slots at high speed where they are abruptly stopped by the stationary side walls of the vertical stator slots and their direction is changed. Material enters the rotor-stator mechanism from top and bottom as shown in Figure 1, generally being aided by low agitation propellers.
After recirculating through the rotor-stator mechanism several times, the peroxide is attrited into very small particles and a proper dispersion is formed. The Kady Mill type dispersion avoids shear as much as possible and, in fact, does not rely upon close tolerance between milling surfaces such as colloid mills, ball and pebble mills, rolling mills and the like. ~ime of operation of the Kady Mill is the controlling actor since fixed clearances are built into the mill. Such type of apparatus is described in Vnited States Patent 2,706,621 to Laird. The Kady Mill i6 furthsr specifically described in Cost Enqineexinq, January 1967, pages 2 through 6.
The g~neral process for producing peroxide dispersions according o the present lnvention includes the steps of adding the partiaular constituents to be dispersed to a low shear impact dispersion unit such as the Kady ~ill in which the dispersion is ~uickly achieved, eg. generally in about three to about seven minutes. The dispersion is then removed from the Kady Mill, vacuum degassed and strained. Preferably, prior ~ 30 to introduction of the mixture to the dispersion mill, at ;~ leaBt a portion of same i~ blended with a low shear mixer as exemp].ified by a jiffy mixer. Utilizing the low ~; shear, impact dispersion mill, it was found that a mixture containing water, peroxide in powder or ; 35 particulate form, and a defoamer became very viscous ,' .' ' `
'. ~
:.
-: : .. :
' ~L2~
- ~4 -virtually as soon as the mill was started. When, however, a compound is added that produces an ionic atmosphere about the peroxide particles, is inert as to the peroxide, and is at least water dispersible, viscosities may be achieved as low as about 100 centipoises, msasured with a Brookfield RVT viscometer, numbex 3 spindle at 50 revolutions per minute. Also, inspection with a microscope at 1,000 magnification indicated that all of the peroxide particles were less than 10 microns in size and that a vast majority of same were from about 2 to about 5 microns in size.
Illustrative of the compounds which produce an ionic region about the particles and permit the viscosity ~` control of the peroxide dispersions in the low shear impact dispersion mill are pyrogenic or fumed silicas (Cab-o-sil silicas manufactured by Cabot Corporation), sodlum salts of condensed naphthalene sulfonic acids (Tamol SN, manufactured by Rohm and Haas Company, Philadelphia, Pennsylvania) and sodium salts of polymerized carboxylic acids (~amol 731, manufactured by Rohm and Haas Company). In selecting a particular dispersant for use in controlling viscosity of the dispersion, as mentioned above same must be inert as to the peroxide. In this regard, any compound should be avoided that will, for example, cause the peroxide to decompose, as well as any dispersant in which the peroxide dissolves ~nd promotes the formation of crystalllne peroxide which is shock sensitive and explosive. ~he ionic region ~3enerating compounds may be present in the dispersions in a range of fro~ about 1 to about 7 weight percent, preferably from about 3 to about 6.
In generating the ionic atmosphere about the peroxide particles, particular dispersants, exemplified 3S Trademark . . .
, . : `
; . ~, . ~
, ~6~146~3 by those set forth above, are employed which supply ions to the area surrounding the peroxide particles. Ions, of course, are charged particles which, depending upon charge on ad;acent particles, will create, attract or repulsive forces with respect thereto. The Tamol dispersants noted above are reported in the literature as surrounding particles with a strong anionically charged electrical layer. It is believed that such charged electrical layer overcomes the attractive forces normally existing between the peroxide particles and keeps the particles`separated.
Since benzoyl peroxide is the preferred peroxide for use according to the present invention, discussion ; hereinafter will be made with respect only to benzoyl peroxide with the understanding that other peroxides within the genu~, would likewise be appropriate.
A dlspersion of benzoyl peroxide, water, Cab-o-sil, and a defoamer will, in a short period of time eg.
~everal days, not remain in the dispersed condition. The .
benzoyl peroxide particles will settIe out, but when subjected to low shear agitation, will go back into suspension. In situations where resuspending of the particles will accomplish the intended result, the above dispersion may suffice, shouid, however, it be desirable to produce a permanent dispersion or suspension, a soluble inorganic salt that is stable to the benzoyl : peroxide may be added. Exemplary of such salts are :~ sodium chloride, potassium chloride, and calcium chloride, as well a6 other chloride salts except those of the transition metals which would cause the benzoyl .
.~ peroxide to decompose. Further exemplary of suitable ~` salts are the soluble phosphate and sulfate salts of the group I and II metals. Bromide and iodide salts should, however, be avoided.
~; 35 Inclusion of further particular ingredients in the .
L~
, :, '~ ~
~ZI~i4~
peroxide compositions when utilizing same to catalyze unsaturated polyester resin E yrups, permit the attainment of a high or a low density polymer product, depending upon the amount of the peroxids composition utilized. A
blowing agent is included which liberatss car~on dioxide, exemplified by carbonates and bicarbonates of groups I or II metals, eg. calcium carbonate or calcium bicarbonate. One sufficient catalyst is included to provide adequate blowing agent for foaming the polymers, foaming wlll occur proportional to the amount present.
A further class of acidic inorganic salts when dissolved in the water phase of the present peroxide compos1tions yields particularly important advantages.
;~ These salts are exemplified by NaH2PO4, Na2HPO4, NaHSO4, or AlCl3, with sodium dihydrogen phosphate and sodium ~: hydrogen phosphate being preferred. The acidic inorganic salt~ (1) increase the specific gravity of the water ~; phase which decreases the propensity of settling of the ~ peroxide; (2) act as a fire retardant for the peroxide in ; 20 suspension; (3) have a humectant effect on the dispersion which reduces the rate of water evaporation therefrom;
and (4) if and when the dispersion dries down or the water is otherwise removed, retain water of hydration which ~ignificantly reduces the flammable and explosive nature of the dry peroxide. In addition, the preferred salts, serve as a buffer to maintain pH of the dispersion in a range of from about 3 to about 8, producs a sequestering effect on the dispersion thu~ reducing decomposition of the peroxide as a result of transition metal ions, and provide a flame retardant effect in both :;` solution and ~olid form. These inorganic salts may be present in the dispersions in a rangs of from about 5 to about 20 weight percent, preferably about 14 to 18 . Additionally othex ingredlents may be added to the dispersions for particular needs so long as no advarse :;-~3 ', .
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effects are produced thereby. For example, a surfactant may be needed for catalysis of certain polyesters, etc.
LiXewise for foamin~, cell stabilizers may be necessary or desirable.
S A better understanding of the present invention will be had by referring to the following examples.
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A mixture of 1500 grams of water, 100 grams of Cab-o-sil , a fumed silica product manufactured by Cabot Corporation and fiO grams of DC-B , a silicone based defoamer manufactured by Dow Corning, Midland, Michigan was added to a low shear mixer and mixed well.
Thereafter, 1906 grams of Lucidol BP0-78 , a particulate ~-~ benzoyl peroxide manufackured by Lucidol Division, ; 15 Pennwalt, Corp., Buffalo, New York, was added to the low shear mixer, mixed in and the mixture was allowed to stand 1 hour. The mixture was then placed in a Kady Mill dispersion unit whi.ch operated for 4.5 minutes, followed by vacuum degassing and straining through an 80 mesh strainer. Visc06ity of the dispersion was measured with a Brookfield RVT viscometer using a number 3 spindle. At 5 rpm a visc06ity reading of 4600 cps. was obtained, while at 50 rpm the visc06ity was 720 cps.
After several days standing undisturbed, the benzoyl peroxide separated from the disper6ion, though thereafter, went back into suspension with low shear agikation. Inspeckion with a microscope at 1000 magnificakion showed all benzoyl peroxide particles to be less than 10 microns, wikh a vask ma~ority of same being a size of from about 2 to about 5 microns. The specific "~ graviky of the dispersion was measured to be 1.158 and ~ peroxide content of 40.9 percenk by weight.
i~ EXAMPLE 2 A mixture of 1200 grams of water, 80 yrams of Cab-o-3S Trademark r ~
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sil and 98 grams of DC-~ defoamer were mixed well in a low shear mixer, after which 2567 grains of Lucidol BP0-78 were added with mixing continuing. ~he overall mixture was then placed in the Kady Mill which operated for three minutes, was removed from the Kady Mill, vacuum degassed and strained through an 80 mesh strainer.
- Viscosity of the dispersion using a number 4 spindle, measured 820 cps. at 100 rpm and 4400 cps. at 10 rpm.
Specific gravity of the dispersion was determined to be 1.150 with 50.2 percent by weight peroxide solids present. The material appeared to be slightly foamed.
ExAMpLE 3 A mixture of 1550 grams water, 60 grams of Cab-o-sil and 80 grams oP DC-120, a silicone based defoamer manufactured by Dow Corning were mixed well in a low shear mixer after which 4022 grams of Luaidol BP0-78 were added and mixed weli. ~his mixture was then placed in the Kady Mill which operated for 7.5 minutes. ~he r~sulting dispersion was removed from the Kady MiIl, vacuum degassed and strained through an 80 mesh strainer.
Viscosity was measured on a Brookfield RVT viscometer with a number 4 spindle to be 1500 cps. at 100 rpm and 6020 at 10 rpm. Speaific gravity of the dispersion was measured at 1.200 with 55.03 percent peroxide solids ;~ 25 present. Examples l through 3 thus indicate preparation ~- of variou~ concentration peroxide dispersions.
Benzoyl peroxide ~BP0) dispersions were produced O.1 the Kady Mill at 35, 40, 45, 50 and 55 weight percent ~ 30 peroxide solids, utilizing proportionate amounts of ;~ water, Cab o~sil and DC-B de~oamer, with the Kady Mill being operated ~or three minutes in each case. Viscosity of each dispersion was measured with a Brookfield viscometer, and results are tabulated in Table 1.
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~ TABLE 1 VISCOSITY OF BPO DISPER~IONS
EXAMPLE NO. 4 S 6 7 8 _ VISCOSITY, CPS. _________ SPEED, RPM
Pounds/Gallon 9.249.35 9.5 9.75 9,g As can be seen from Table I, dispersion viscosities varied from 40 cps. to 8000 cps., depending upon concentration of peroxide solids and the viscosity measurement technique. For a number 3 spindle at 50 rpm, ;~ viscosity ranged from 70 cps. to 620 aps.
EXAMP~ES 9 - 13 A quantity of sodium dihydrogen phosphate was added ~; 20 to each of the dispsrsions of Examples 4 - 8 to produce a 20 weight percent solution of same in the water phase.
Viscosities of the dispersions were then measured.
Results were tabulated in Table II.
TABLE II
VISCOSITY OF BPO-NaH2PO4 DISPERSION
EXAMPLE NO. 9~Q ll 12 13 SPINDLE NO. 23 3 3 4 VIS~O~ITY, CPS.
RVT,RPM 100 60 90 200 810 2500 120250 600 26~0 7000 ~ 10 200 400 1050470Q 1100 ; POUNDS/GA~LON 10.1 10.2 10.3 10.5 10.55 :~ .
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As can be seen from Table II the addition of the sodium dihydrogen phosphate increased viscosities across the board.
.EXAMPLES 14 - 19 A series of BPO dispersions were prepared containing the same percent BP0, DC-B defoamer and water while varylng the level of Cab-o-sil. Each sample was prepared in exactly the same manner. The water, DC-~ defoamer and Cab-o-sil were mixed. The BPO was mixed in slowly in the low shear mixer. The mixtures were subjected to the Kady Mill for an operating time of six minutes. Each sample was then vacuum de~assed and strained. The base constituent mix incluaed 1550 grams of water, 100 grams ;~ of DC-B defoamer, and 3200 grams BPO-78. The Cab-o-sil fumed silica was varied as shown in Table III below with the attendant viscosity measurement for the dispersions~
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As oan he seen ~rom Table III, viscosity followed a U shaped curve. At 0 percent Cab-o-sil, the viscosity was very high, decreasing at 25, 50 and 75 gram levels, then increasing at 100 and 150 gram levels. Such ~as not predicted since Cab-o-sil is marketed as a product to increase viscosity.
EXAMP~ES 19 - 24 Eight hundred grams of each o~ Examples 14 - 19 were mixed well at low shear with 150 grams of sodium dihydrogen phosphate. The sampl~es were left overnight, then vaouum degassed, and visoosity of the dispersion measured. Results are tabulated in Table IV.
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-24- ~ 68 As can be seen from Table IV, the U shaped curve continues to exist, though at a higher plateau.
The samples containing 25, 75 and 100 grams fumed-silica (Examples 15, 17, and 18) were mixed together with low shear for one hour. The Ini x was prepared to be comparable to the original formulation containing 72 grams The viscosity of the resultiny mix was measured with a number 4 spindle and indicated 1250 cps. a~ 100 rpm, 2200 cps. at 50 rpm, 3900 cps. at 20 xpm, 6800 cps.
at 10 rpm and 12350 cps. at 5 rpm. The samples containing 0 and 25 (Examples 14 and 15) grams fumed silica when inspected under the ~icroscope showed the peroxide particles had been broken up and then reaggregated.
A dispersion containing 1550 grams of water, 100 grams of DC -B and 2893 grams of Lucidol BPO-78 was prepared in a low shear mixer as set forth in Example 1.
The mixture was thsn placed in the ~ady Mill for a 1 minute operation. The mixture became so viscous that the mill would not grind. Examination under the microscope indicated reaggregation of the peroxide particles.
Viscosity was tested with a RVT Helipath unit using ` ' 25 Spindle F at 1 rpm and found to be 400 x 106 cps. Sixty grams of Cab o-sil were slowly added to the viscous mix ~ at low shear. Mix viscosity began to drop and the mix ; began to degas. After being mixed well the viscosity of the mix was determined by Brookfield RVT Spindle No. 4 to be 1500 cps. at 100 rpm, 2320 cps. at S0 rpm, 4900 cps.
at 20 rpm and 8000 ~ps. at 10 rpm. The mixture was returned to the Kady Mill for an additional 3 minute operation, removed and degass~d. Viscosity at 50 rpm was 4000 cps. ~hree hundred grams of Tamol SN was slowly ~ mixed in well with low shear. Viscosity dropped to 2500 aps. at 50 rpm. The sample was then vaauum degassed and the visaosity mea~ured using a number 3 spindls.
Visaosity was 7200 cps. at 5 rpm, 4750 aps. at 10 rpm, ~' 1'``' ,~ "'' : ~
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2150 cps. at 20 rpm, 1100 cps. at 50 rpm, and 650 cps. at 100 rpm. Again it is seen that viscosity is in part co~trolled by the fumed silica and a sodium salt of condensed naphthalene sulfuric acid.
A series of dispersions were produced with the constituents as specified in Example 16 with the exception that the level of benzoyl peroxide varied on a weight percent basls as set forth in ~able V below, -~ 10 containing 35, 40, 45, 50, 55, 60 and 65 weight percent benzoyl peroxide. Viscosi~y of the dispersions was measured with a Brookfield viscometer. Results are tabulated in Table V.
TABLE V
VISCOSITY OF BENZOYL PEROXIDE DISPERSIONS
EXAMPLE NO. 27 28 29 BENZOYL PEROXIDE, % 35% 40% 45%
Spindle/rpm- 2/100 = 120 3/100 = 200 3/100 - 350 Vis~.,cps. 2/5~ = 144 3/50 = 280 3/50 = 520 ~` 20 2/20 = 240 3/20 = 175 3/20 = 900 2/10 = 380 3/10 = 750 3/10 = 1500 2/5 = 640 3/5 = 1200 3/5 = 2600 EXAMPhE NO. 30 31 32 ,.i BENZOY~ PEROXIDE, % 50% S5% 60%~Heliapath) .~ . .
Spindle/rpm- 3/100 = 500 5/100 = 1840 D/5 14.8 x 10 Visc.,cps. 3/50= 820 5/50 = 3120 D/25 23.6 x 10
3/20=1575 5/20 = 6400 D/1 38.6 x 10 3/10=2700 5/10 =11800 3/5=4650 5/5 =20800 EXAMPLE NO. ~33 ~ BENZOYL PEROXIDE, % 65%
; Spindle/rpm- Semi-Solid ; Visa., cps. muah like molding alay , , ~ 35 Similar viscosity piatures are presented as ., ,, . .- ~:
6~3 represented in the Examples set forth above.
A seventy percent by weight benzoyl peroxide dispersion was produced as described in Example 1.
Thirty grams of water, and 29 grams of Tamol 731, a sodium salt of a carboxylated polyelectrolyte manufactured by Rohm and Haas were blended together.
Thereafter five hundred eighty eight grams of Lucidol BPO-78 were 610wly added and mixed well with low shear into the blend. The mix was then placed in the Kady Mill for 30 seaonds operation. The sample was removed, cooled, degassed and Brookfield ViSGosity measurea.
Using a number 3 spindle, viscosities were 5600 cps. at - 100 rpm, 8000 cps. at 50 rpm, 12000 cps. at 20 rpm, 16000 cps. at 10 rpm and 20000 cps. at 5 rpm. Solids content of the benzoyl peroxide was measured at 70.1 weight percent, thus indica~ing the feasibility of producing high concentrate peroxide dispersions.
. ~
~ 20 Fifty grams of an unsaturated polyaster resin - (Owens-Corning Low Profile for boat spray-up) were mixed with 0.005 grams of N, N, dimethyl aniline. One gram of the benzoyl peroxide dispersion described in Example 1 was added and the constituents mixed for 60 seconds with low shear. The mixture did not gel in four hours.
slide of the liquid that was prepared and inspected under the microsoope at 100 magnification showed that the benzoyl peroxide particles in the dispersion had reaggregated, and not dissolved in the polyester resin, ~ 30 thus negating the catalytic action of the peroxide.
;~; EXAMPLE 36 ::
~ Example 35 was repeated with the exception that one -~ gram of Dow Corning 193 Silicon fluid (a surfactant) was ~ included. The resin gelled in 30 minutes, indicating the : 35 need for a surfactant for certain resin~ to assist in the .
:' ''`'"' dil3solution of the peroxide catalyst.
A mixture was produced which included 1500 grams of water, 400 grams of Tamol SN, 500 grams of NaH2PO4, 50 grams of Cab-o-sil, and 25 grams of DC-R. The formulation was mlxed well, and 4515 grams of Lucidol BPO-78 was slowly addea with low shear, stirring continuing for two hours. Thereafter, the mix was placed in the Kady Mill which was operated for five minutes, ~ 10 removed, cooled, degassed and the Brookfield viscosity -~ measured with a number 3 spindle. Dispersion viscosity was 450 cps. at 100 rpm, 720 aps. at 50 rpm, 1450 cps. at 20 rpm, and 2500 aps. at 10 rpm. Weight of the dispersion was 10.23 pounds per gallon with 50.4 weight percent peroxide solids present.
Two grams of the dispersion of Example 37 were ~i. mixed with 0.025 grams of N, N, dimethyl aniline. The sample slowly turned green, though no heat was generated.
~-~ 20 One hour later, the mixture was added to fifty grams o~
the unsaturated polyeæter resin of Example 35. Gelling of the resin occurred in 25 minutes.
~` E~AMPLE 39 Two grams of commercially available Cadox 40E, a 40 weight perce.nt benzoyl peroxide dispersed in plasticizer ~ produced by Noury was mixed thoroughly with 0.025 grams -~ N,N, dimethyl aniline. The sample rapidly turned purple, ~ and in about five minutes turned black. No exotherm was ;~ detected. One hour later the material was added to 50 -~ 30 grams of the unsaturated polyester resin of Example 35.
The resin had not gelled in five hours, though a rubber-liXe gel occurred in about 15~hours.
One thousand grams of Alpha Resin Grade 80, Alpha Trademark ' ' ' . .
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.
' Resin Collierville, Tennessee 38017 was blended with 400 grams CaC03 (Gamma Sperse 6532 from Georgia Marble, Tate, Georgia 30177) along with 1.4 grams of N,N, Dimethyl aniline, and 14 grams of Dow Corning 193 surfactant. Fifty grams of the above formulation were mixed well with one gram of the benzoyl peroxide dispersion of Example 37. Ths resin gelled in approximately 20 minutes and was cured in 1 hour, indicating successful catalysis. Fifty grams of the resin formulation were also mixad well with one gram of the benzoyl peroxide dispersion of Example 12. The resin gelled in approximately 25 minutes, and was cured in approximately one hour with no ~ignificant increase in - volume. Fity grams of the resin formulation were mixed well with two grams of the peroxide dispersion of Example 12. The resin gelled in approximately 20 minutes, and : was cured in approximately one hour with an increase in ~; volume of approximately 50 percent, thus indiaating some foaming. Fi f ty grams of the resin formulation were blended with five g~.ams NaHCO3 and one gram of the benzoyl peroxi~e dispersion of Example 12 was mixed with the resln system. The resin gelled in approximately 25 minutes and increased in volume of approximately 100 percent, indicating significant foaming.
EXAMPkE 41 Two 4 oz. paper aups were inverted revealing a circular cavity approximately 1 3/4 inches in diameter and 3/8 inch deap. The cavitie~ were filled with the benzoyl peroxide dispersion of Example 37. The cup was ~; 30 placed on a conarete surface and set on fire. The paper cup burned up, though only a very small amount of the benzoyl peroxide dispersion appeared to burn, but without any ignition. A third aup was set aside to dry, with the dispersion (Example 37) in the circular cavity. The ~rademark .:
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~ , dispersion required seven days for evaporation of the Water phase under laboratory conditions. When dry, the cup was set on fire on a concrete pad. The paper cup burned up and the dried ben~oyl peroxide ignited and slowly burned. A fourth paper cup Wc19 inverted and filled with a commercial benzoyl peroxide powder, BPO-78 manufactured by Witco. The cup was set on fire. The cup burned up and the peroxide burned in a flash.
A 300 gram sample of the benzoyl peroxide dispersion - descrlbed in Example 37 (containing NaH2PO4) was placed on a porous paper towel. After standing under laboratory conditions for 24 hours, a very thiak white paste was formed. ~he paste was placed in a glass beaker and 90 grams of Cab-o-sil fumed silica was blended therewith.
With little blending the paste turned into a free-~lowing powder, which was sievsd through a 100 mesh sareen. A
small sample of about one gram of the peroxide powder was plaaed in an open flame where it burned slowly. A
similar sized sample of commercial benzoyl peroxide powder, BPO-78 , was placed in the flame and burned with a flash. ~his Example illustrates the ability of ~ producing a powder form of benzoyl peroxide which is not ;~ ~ classified as flammable or explosive.
Benzoyl peroxide disper6ion of Example 37 was placed in a Glasscraft Model 88 pressure pot catalyzer. A 5/16 inah catalyst line connected the pressure pot to a spray ;~ gun which was a Polycrat 505H with a standard Glasscraft Chopper mounted on the gun. Owens ~orning Fiberglas 32H, an unsaturated gensral purpose polyester resin activated with 1% N, N, Dimethyl aniline and 1% DC-193 surEactant was employed. Resin was dellvered to the spray gun tip by a Binkæ/Streach Hornet pump. The system was * Trademark "' i~
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pressuriæed, with the catalyst pot at 50 psi and resin fluid pressure at approximately 800 psi. Catalyst and resin both sprayed in a normal manner and the resin cured normally. The catalyst and resin mixed very well and no appreciable difference was detected between this procedure and commercial procedures.
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6~3 represented in the Examples set forth above.
A seventy percent by weight benzoyl peroxide dispersion was produced as described in Example 1.
Thirty grams of water, and 29 grams of Tamol 731, a sodium salt of a carboxylated polyelectrolyte manufactured by Rohm and Haas were blended together.
Thereafter five hundred eighty eight grams of Lucidol BPO-78 were 610wly added and mixed well with low shear into the blend. The mix was then placed in the Kady Mill for 30 seaonds operation. The sample was removed, cooled, degassed and Brookfield ViSGosity measurea.
Using a number 3 spindle, viscosities were 5600 cps. at - 100 rpm, 8000 cps. at 50 rpm, 12000 cps. at 20 rpm, 16000 cps. at 10 rpm and 20000 cps. at 5 rpm. Solids content of the benzoyl peroxide was measured at 70.1 weight percent, thus indica~ing the feasibility of producing high concentrate peroxide dispersions.
. ~
~ 20 Fifty grams of an unsaturated polyaster resin - (Owens-Corning Low Profile for boat spray-up) were mixed with 0.005 grams of N, N, dimethyl aniline. One gram of the benzoyl peroxide dispersion described in Example 1 was added and the constituents mixed for 60 seconds with low shear. The mixture did not gel in four hours.
slide of the liquid that was prepared and inspected under the microsoope at 100 magnification showed that the benzoyl peroxide particles in the dispersion had reaggregated, and not dissolved in the polyester resin, ~ 30 thus negating the catalytic action of the peroxide.
;~; EXAMPLE 36 ::
~ Example 35 was repeated with the exception that one -~ gram of Dow Corning 193 Silicon fluid (a surfactant) was ~ included. The resin gelled in 30 minutes, indicating the : 35 need for a surfactant for certain resin~ to assist in the .
:' ''`'"' dil3solution of the peroxide catalyst.
A mixture was produced which included 1500 grams of water, 400 grams of Tamol SN, 500 grams of NaH2PO4, 50 grams of Cab-o-sil, and 25 grams of DC-R. The formulation was mlxed well, and 4515 grams of Lucidol BPO-78 was slowly addea with low shear, stirring continuing for two hours. Thereafter, the mix was placed in the Kady Mill which was operated for five minutes, ~ 10 removed, cooled, degassed and the Brookfield viscosity -~ measured with a number 3 spindle. Dispersion viscosity was 450 cps. at 100 rpm, 720 aps. at 50 rpm, 1450 cps. at 20 rpm, and 2500 aps. at 10 rpm. Weight of the dispersion was 10.23 pounds per gallon with 50.4 weight percent peroxide solids present.
Two grams of the dispersion of Example 37 were ~i. mixed with 0.025 grams of N, N, dimethyl aniline. The sample slowly turned green, though no heat was generated.
~-~ 20 One hour later, the mixture was added to fifty grams o~
the unsaturated polyeæter resin of Example 35. Gelling of the resin occurred in 25 minutes.
~` E~AMPLE 39 Two grams of commercially available Cadox 40E, a 40 weight perce.nt benzoyl peroxide dispersed in plasticizer ~ produced by Noury was mixed thoroughly with 0.025 grams -~ N,N, dimethyl aniline. The sample rapidly turned purple, ~ and in about five minutes turned black. No exotherm was ;~ detected. One hour later the material was added to 50 -~ 30 grams of the unsaturated polyester resin of Example 35.
The resin had not gelled in five hours, though a rubber-liXe gel occurred in about 15~hours.
One thousand grams of Alpha Resin Grade 80, Alpha Trademark ' ' ' . .
..::.: , ......
.
' Resin Collierville, Tennessee 38017 was blended with 400 grams CaC03 (Gamma Sperse 6532 from Georgia Marble, Tate, Georgia 30177) along with 1.4 grams of N,N, Dimethyl aniline, and 14 grams of Dow Corning 193 surfactant. Fifty grams of the above formulation were mixed well with one gram of the benzoyl peroxide dispersion of Example 37. Ths resin gelled in approximately 20 minutes and was cured in 1 hour, indicating successful catalysis. Fifty grams of the resin formulation were also mixad well with one gram of the benzoyl peroxide dispersion of Example 12. The resin gelled in approximately 25 minutes, and was cured in approximately one hour with no ~ignificant increase in - volume. Fity grams of the resin formulation were mixed well with two grams of the peroxide dispersion of Example 12. The resin gelled in approximately 20 minutes, and : was cured in approximately one hour with an increase in ~; volume of approximately 50 percent, thus indiaating some foaming. Fi f ty grams of the resin formulation were blended with five g~.ams NaHCO3 and one gram of the benzoyl peroxi~e dispersion of Example 12 was mixed with the resln system. The resin gelled in approximately 25 minutes and increased in volume of approximately 100 percent, indicating significant foaming.
EXAMPkE 41 Two 4 oz. paper aups were inverted revealing a circular cavity approximately 1 3/4 inches in diameter and 3/8 inch deap. The cavitie~ were filled with the benzoyl peroxide dispersion of Example 37. The cup was ~; 30 placed on a conarete surface and set on fire. The paper cup burned up, though only a very small amount of the benzoyl peroxide dispersion appeared to burn, but without any ignition. A third aup was set aside to dry, with the dispersion (Example 37) in the circular cavity. The ~rademark .:
~ .
;
~ , dispersion required seven days for evaporation of the Water phase under laboratory conditions. When dry, the cup was set on fire on a concrete pad. The paper cup burned up and the dried ben~oyl peroxide ignited and slowly burned. A fourth paper cup Wc19 inverted and filled with a commercial benzoyl peroxide powder, BPO-78 manufactured by Witco. The cup was set on fire. The cup burned up and the peroxide burned in a flash.
A 300 gram sample of the benzoyl peroxide dispersion - descrlbed in Example 37 (containing NaH2PO4) was placed on a porous paper towel. After standing under laboratory conditions for 24 hours, a very thiak white paste was formed. ~he paste was placed in a glass beaker and 90 grams of Cab-o-sil fumed silica was blended therewith.
With little blending the paste turned into a free-~lowing powder, which was sievsd through a 100 mesh sareen. A
small sample of about one gram of the peroxide powder was plaaed in an open flame where it burned slowly. A
similar sized sample of commercial benzoyl peroxide powder, BPO-78 , was placed in the flame and burned with a flash. ~his Example illustrates the ability of ~ producing a powder form of benzoyl peroxide which is not ;~ ~ classified as flammable or explosive.
Benzoyl peroxide disper6ion of Example 37 was placed in a Glasscraft Model 88 pressure pot catalyzer. A 5/16 inah catalyst line connected the pressure pot to a spray ;~ gun which was a Polycrat 505H with a standard Glasscraft Chopper mounted on the gun. Owens ~orning Fiberglas 32H, an unsaturated gensral purpose polyester resin activated with 1% N, N, Dimethyl aniline and 1% DC-193 surEactant was employed. Resin was dellvered to the spray gun tip by a Binkæ/Streach Hornet pump. The system was * Trademark "' i~
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pressuriæed, with the catalyst pot at 50 psi and resin fluid pressure at approximately 800 psi. Catalyst and resin both sprayed in a normal manner and the resin cured normally. The catalyst and resin mixed very well and no appreciable difference was detected between this procedure and commercial procedures.
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Claims (31)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An improved organic peroxide dispersion comprising:
a) from about 35 to about 70 weight percent of organic peroxide having a particle size of about 10 microns or less;
b) from about 65 to about 30 weight percent water;
and c) an amount of a water dispersible, ionic region producing dispersant which is insert as to said peroxide that produces an ionic region about said peroxide and which produces a dispersion having a predetermined viscosity which may be as low as about 100 centipoises when measured with a Brookfield RVT viscometer using a number 3 spindle at 50 revolutions per minute.
a) from about 35 to about 70 weight percent of organic peroxide having a particle size of about 10 microns or less;
b) from about 65 to about 30 weight percent water;
and c) an amount of a water dispersible, ionic region producing dispersant which is insert as to said peroxide that produces an ionic region about said peroxide and which produces a dispersion having a predetermined viscosity which may be as low as about 100 centipoises when measured with a Brookfield RVT viscometer using a number 3 spindle at 50 revolutions per minute.
2. An organic peroxide dispersion as defined in claim 1 wherein the peroxide is benzoyl peroxide.
3. An organic peroxide dispersion as defined in claim 1 comprising further d) a defoamer.
4. An organic peroxide as defined in claim 3 comprising further e) an amount of a water soluble inorganic salt adequate to prevent said peroxide particles from settling out of the dispersion, said inorganic salt being inert as to said peroxide.
5. An organic peroxide dispersion as defined in claim 4 wherein the inorganic salt is selected from the group consisting of chloride, phosphate and sulfate salts.
6. An organic peroxide dispersion as defined in claim 1 comprising further an acidic inorganic salt that dissolves in the water phase increases the specific gravity of the dispersion, and upon drying down of the dispersion, retains water of hydration, whereby the flammable and explosive nature of the peroxide is diminished.
7. An organic peroxide dispersion as defined in claim 6 wherein said salt is selected for the group consisting of NaH2PO4, Na2HPO4, NaHSO4, and AlC13.
8. An organic peroxide dispersion as defined in claim 1 comprising further a blowing agent.
9. An organic peroxide dispersion as defined in claim 8 wherein the blowing agent is a salt that liberates carbon dioxide.
10. An organic peroxide dispersion as defined in claim 9 wherein the blowing agent is selected from the group consisting of carbonates and bicarbonates of Group I and II transition metals, and mixtures of same.
11. An organic peroxide aqueous dispersion comprising:
a) from about 35 to about 70 weight percent of organic peroxide particles, said particles having a size of about 10 microns or less;
b) water;
c) a compound that produces an ionic region about the peroxide particles in the dispersion, is inert as to the peroxide, and is at least water dispersible;
d) a defoamer; and e) a water soluble inorganic salt which is inert as to the peroxide, increases the viscosity of the dispersion, retains water of hydration upon dry down of the dispersion and possesses fire retardant properties.
a) from about 35 to about 70 weight percent of organic peroxide particles, said particles having a size of about 10 microns or less;
b) water;
c) a compound that produces an ionic region about the peroxide particles in the dispersion, is inert as to the peroxide, and is at least water dispersible;
d) a defoamer; and e) a water soluble inorganic salt which is inert as to the peroxide, increases the viscosity of the dispersion, retains water of hydration upon dry down of the dispersion and possesses fire retardant properties.
12. An organic peroxide as defined in claim 11 wherein the peroxide is benzoyl peroxide.
13. An organic peroxide as defined in claim 12 where the ionic region producing compound in a finely divided fumed silica.
14. An organic peroxide as defined in claim 12 wherein the ionic region producing compound is a sodium salt of a condensed naphthalene sulfonic acid.
15. An organic dispersion as defined in claim 12 wherein the ionic region producing compound is a sodium salt of a polycarboxylic acid.
16. An organic peroxide dispersion as defined in claim 11 wherein the soluble salt is a member selected from the group consisting of NaH2PO4, Na2HPO4, NaHSO4, and AlCl3.
17. An organic peroxide dispersion as defined in claim 11 comprising further a blowing agent.
18. An organic peroxide dispersion as defined in claim 17 wherein the blowing agent is member selected from the group consisting of carbonates and bicarbonates of Group I and II transition metals.
19. A process for producing an improved organic peroxide dispersion comprising the steps of:
a) providing a mixture of at least organic peroxide particles, having a particle size of about 10 microns or less water; and a water dispersible ionic region producing dispersant that produces an ionic region about the peroxide particles in the dispersion and is inert as to the peroxides; and b) subjecting the mixture to a low shear impact type dispersion mill for a predetermined period of time.
a) providing a mixture of at least organic peroxide particles, having a particle size of about 10 microns or less water; and a water dispersible ionic region producing dispersant that produces an ionic region about the peroxide particles in the dispersion and is inert as to the peroxides; and b) subjecting the mixture to a low shear impact type dispersion mill for a predetermined period of time.
20. A process as defined in claim 19 wherein viscosity of the dispersion is determined by the amount of said ionic region producing compound that is present and the time of operation of the dispersion mill, and may be as low as about 100 centipoises when measured on a Brookfield RVT viscometer using a number 3 spindle at 50 revolutions per minute.
21. A process is defined in claim 20 wherein at least a portion of the mixture is blended under low shear conditions prior to introduction to the impact type dispersion mill.
22. A process as defined in claim 19 wherein the impact type dispersion mill includes a rotor defining tangential slots therein, said rotor being located within a stationary stator having radial slots therein and when said mixture is impacted against said stator to attrite said peroxide particles.
23. A process as defined in claim 19 wherein said mixture includes a water soluble inorganic salt that is inert to said peroxide, increases specific gravity of said dispersion and retains water of hydration upon dry down of the dispersion.
24. A process as defined in claim 19 wherein the resulting viscosity of said dispersion is from about 100 to about 3000 centipoises when measured with a Brookfield RVT viscometer using a number 3 spindle at 50 revolutions per minute, whereby said dispersion is sprayable.
25. An improved aqueous dispersion of an organic peroxide comprising:
a) from about 35 to about 70 weight percent of particulate organic peroxide, said particles having a size of about 10 microns or smaller;
b) from about 65 to about 30 weight percent water;
c) from about 1 to about 7 weight percent of a water dispersible, ionic region producing dispersant that produces an ionic region about the peroxide particles in the dispersion and is inert as to the peroxide;
d) a defoamer; and e) a water soluble inorganic salt that is inert as to the peroxide, increase specific gravity of the dispersion and retains water of hydration upon drying down of the dispersion.
a) from about 35 to about 70 weight percent of particulate organic peroxide, said particles having a size of about 10 microns or smaller;
b) from about 65 to about 30 weight percent water;
c) from about 1 to about 7 weight percent of a water dispersible, ionic region producing dispersant that produces an ionic region about the peroxide particles in the dispersion and is inert as to the peroxide;
d) a defoamer; and e) a water soluble inorganic salt that is inert as to the peroxide, increase specific gravity of the dispersion and retains water of hydration upon drying down of the dispersion.
26. An organic peroxide dispersion as defined in claim 25 wherein the peroxide is selected from the group consisting of benzoyl peroxide, lauroyl peroxide, di-cumyl peroxide, di-cetyl peroxydicarbonate, and mixtures of same.
27. An organic peroxide dispersion as defined in claim 25 wherein the ionic region producing compound is selected from the group consisting of fumed silica, salts of condensed napthalene sulfunic acids, salts of polymerized carboxylic acids and mixtures of same.
28. An organic peroxide dispersion as defined in claim 25 wherein the water soluble inorganic salt is selected from the group consisting of NaH2PO4, NaH2PO4, NaH2HSO4, AlCl3 and mixtures of same.
29. An organic peroxide dispersion as defined in claim 25 comprising further a blowing agent.
An organic peroxide dispersion as defined in
29. An organic peroxide dispersion as defined in claim 25 comprising further a blowing agent.
An organic peroxide dispersion as defined in
claim 29 wherein the blowing agent is selected from the group consisting of carbonates and bicarbonates of Group
I and Group II transition metals and mixtures of same.
31. A process for producing a free flowing powder organic peroxide that is characterized as slow burning and non-explosive comprising of the steps of;
a) preparing a mixture of organic peroxide particles having a particles size of about 10 microns or less water, a dispersant that produces an ionic region about the peroxide particles in dispersion and a water soluble inorganic salt that is inert as to the peroxide and retains water of hydration upon drying down of a dispersion;
b) subjecting the mixture to a low shear, impact type dispersion mill for a predetermined period of time;
whereby a dispersion is formed;
c) removing the dispersion;
d) drying down the dispersion to a paste form; and e) blending an amount of fumed silica therewith adequate to convert the peroxide particle to a free flowing powder.
a) preparing a mixture of organic peroxide particles having a particles size of about 10 microns or less water, a dispersant that produces an ionic region about the peroxide particles in dispersion and a water soluble inorganic salt that is inert as to the peroxide and retains water of hydration upon drying down of a dispersion;
b) subjecting the mixture to a low shear, impact type dispersion mill for a predetermined period of time;
whereby a dispersion is formed;
c) removing the dispersion;
d) drying down the dispersion to a paste form; and e) blending an amount of fumed silica therewith adequate to convert the peroxide particle to a free flowing powder.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/567,664 US4917816A (en) | 1984-01-03 | 1984-01-03 | Stabilized peroxide compositions and process for producing same |
| US567,664 | 1984-01-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1264468A true CA1264468A (en) | 1990-01-16 |
Family
ID=24268117
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000471285A Expired - Lifetime CA1264468A (en) | 1984-01-03 | 1985-01-02 | Peroxide compositions and process for producing same |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4917816A (en) |
| CA (1) | CA1264468A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE107277T1 (en) * | 1990-02-07 | 1994-07-15 | Akzo Nobel Nv | AGGLOMERATION OF SOLID PEROXIDES. |
| US5370818A (en) * | 1993-05-28 | 1994-12-06 | Potters Industries, Inc. | Free-flowing catalyst coated beads for curing polyester resin |
| US5690856A (en) * | 1995-03-07 | 1997-11-25 | Akzo Nobel N.V. | Solid diacyl organic peroxide dispersions |
| GB9611806D0 (en) * | 1996-06-06 | 1996-08-07 | Ici Plc | Method of reinforcing an article |
| AU6283299A (en) * | 1998-10-01 | 2000-04-17 | Elan Pharma International Limited | Controlled release nanoparticulate compositions |
| US8236352B2 (en) * | 1998-10-01 | 2012-08-07 | Alkermes Pharma Ireland Limited | Glipizide compositions |
| US8293277B2 (en) * | 1998-10-01 | 2012-10-23 | Alkermes Pharma Ireland Limited | Controlled-release nanoparticulate compositions |
| US20040013613A1 (en) * | 2001-05-18 | 2004-01-22 | Jain Rajeev A | Rapidly disintegrating solid oral dosage form |
| US7521068B2 (en) * | 1998-11-12 | 2009-04-21 | Elan Pharma International Ltd. | Dry powder aerosols of nanoparticulate drugs |
| US20040115134A1 (en) * | 1999-06-22 | 2004-06-17 | Elan Pharma International Ltd. | Novel nifedipine compositions |
| US7198795B2 (en) | 2000-09-21 | 2007-04-03 | Elan Pharma International Ltd. | In vitro methods for evaluating the in vivo effectiveness of dosage forms of microparticulate of nanoparticulate active agent compositions |
| DE60205339T2 (en) * | 2001-02-14 | 2006-05-24 | The Procter & Gamble Company, Cincinnati | MACHINE DISHWASHER CONTAINING DIACYLPEROXIDE BLEACHING AGENT AND HYDROPHOBIC FRAGRANCES |
| US20040101566A1 (en) * | 2002-02-04 | 2004-05-27 | Elan Pharma International Limited | Novel benzoyl peroxide compositions |
| PT1471887E (en) | 2002-02-04 | 2010-07-16 | Elan Pharma Int Ltd | Nanoparticulate compositions having lysozyme as a surface stabilizer |
| US20080220075A1 (en) * | 2002-03-20 | 2008-09-11 | Elan Pharma International Ltd. | Nanoparticulate compositions of angiogenesis inhibitors |
| ATE343376T1 (en) * | 2002-03-20 | 2006-11-15 | Elan Pharma Int Ltd | NANOPARTICLE COMPOSITIONS OF ANGIOGENESIS INHIBITORS |
| US6764612B2 (en) * | 2002-03-22 | 2004-07-20 | Geo Specialty Chemicals, Inc. | Encapsulated peroxide compositions |
| US6699403B2 (en) * | 2002-03-22 | 2004-03-02 | Geo Specialty Chemicals, Inc. | Supported peroxides |
| WO2004006959A1 (en) * | 2002-07-16 | 2004-01-22 | Elan Pharma International, Ltd | Liquid dosage compositions of stable nanoparticulate active agents |
| US7005549B2 (en) * | 2003-01-06 | 2006-02-28 | Hobson David W | Peracid precursors for antimicrobial use |
| US7615187B2 (en) * | 2003-01-06 | 2009-11-10 | D H Technologies, LLP | Organic peroxyacid precursors |
| US7307191B2 (en) * | 2003-01-06 | 2007-12-11 | Oh Technologies Llp | Organic peroxyacid precursors |
| DE102009046251A1 (en) | 2009-10-30 | 2011-05-19 | Evonik Röhm Gmbh | Reactive 1-component road markings |
| EP3211996A1 (en) * | 2014-10-28 | 2017-09-06 | Akzo Nobel Chemicals International B.V. | A method of controling microbial pathogens on living plant tissue |
| CN114149876A (en) * | 2016-06-09 | 2022-03-08 | 阿科玛股份有限公司 | Organic peroxide dispersions |
| CN113292471A (en) * | 2021-06-11 | 2021-08-24 | 山东阳谷华泰化工股份有限公司 | Preparation method of micron-sized powdered dibenzoyl peroxide |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3181991A (en) * | 1961-08-07 | 1965-05-04 | U S Peroxygen Corp | Pigmented peroxide compositions |
| US3182026A (en) * | 1962-03-14 | 1965-05-04 | U S Peroxygen Corp | Homogeneous pigmented peroxide compositions |
| US3224983A (en) * | 1962-05-21 | 1965-12-21 | Scott Paper Co | Process of foaming a carbonate containing polymer containing an initiator |
| DE1243872B (en) * | 1964-08-28 | 1967-07-06 | Glanzstoff Ag | Production of foam plastics from polyesters and polycarbonates |
| US3507800A (en) * | 1966-10-05 | 1970-04-21 | U S Peroxygen Corp | Flame resistant peroxides |
| US4016112A (en) * | 1972-01-28 | 1977-04-05 | Teijin Limited | Process for production of foamed resin structure |
| US3884844A (en) * | 1974-03-11 | 1975-05-20 | Mark Plunguian | Process for forming foamed polyester resins |
| US3920589A (en) * | 1974-07-18 | 1975-11-18 | Stepan Chemical Co | Low-density polyester resin foams and method of preparation |
| US4119583A (en) * | 1975-11-13 | 1978-10-10 | Klf Inventions And Patent Development And Marketing Corporation Ltd. | Foamed articles and methods for making same |
| US4028289A (en) * | 1976-10-05 | 1977-06-07 | Vast Products Inc. | Foamed polyester resin |
| US4155738A (en) * | 1978-03-30 | 1979-05-22 | Allergan Pharmaceuticals, Inc. | Method of stabilizing a peroxide-containing composition |
| US4255277A (en) * | 1979-01-29 | 1981-03-10 | General Electric Company | Storage stable peroxide paste composition |
| JPS5728106A (en) * | 1980-07-25 | 1982-02-15 | Nippon Oil & Fats Co Ltd | Organic peroxide emulsified in water |
| GR75893B (en) * | 1981-03-14 | 1984-08-02 | Sterwin Ag | |
| US4401835A (en) * | 1981-09-17 | 1983-08-30 | Warner-Lambert Company | Method for preparing small sized benzoyl peroxide crystals |
-
1984
- 1984-01-03 US US06/567,664 patent/US4917816A/en not_active Expired - Lifetime
-
1985
- 1985-01-02 CA CA000471285A patent/CA1264468A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4917816A (en) | 1990-04-17 |
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